Human rhinoviruses are the most important causative agents of upper respiratory infections and are also implicated in more severe clinical entities. Although often present, very little is known about human rhinoviruses. Molecular methods have been used in the classification of this large group of viruses into two separate clades. In addition, one known serotype was found to be a member of enterovirus group D. Laboratory diagnosis of human rhinovirus infection is based on reverse transcription polymerase chain reaction methods or the more tedious virus culture but a rapid "bedside" method is unavailable. Anti-rhinoviral therapy has been under extensive study over the past few decades but symptomatic treatment of the common cold is still the only useful approach in clinical use. More data on circulating human rhinovirus strains would facilitate both detection and treatment of these common pathogens.